OBJECTIVE: To investigate the efficacy of ultrasound-guided transabdominal follicular aspiration when the ovaries are not accessible transvaginally. DESIGN: Retrospective case-control study. SETTING: University-hospital based in vitro fertilization (IVF) clinic. PATIENT(S): 69 women undergoing transabdominal follicular aspiration for oocyte retrieval, including 12 cases of mixed abdominal/vaginal aspiration, compared with controls matched by age, follicle number, and year of procedure undergoing standard transvaginal aspiration. INTERVENTION(S): Transabdominal follicular aspiration when one or more ovaries could not be retrieved via standard transvaginal aspiration. MAIN OUTCOME MEASURE(S): Total and mature oocytes retrieved, damaged oocytes, fertilization rate, embryo number and quality, and clinical and ongoing pregnancy rates. RESULT(S): Cases of transabdominal aspiration had slightly fewer oocytes retrieved, but no statistically significant differences were found for damaged oocytes, fertilization rates, embryo number and quality, or pregnancy rates. In 12 years, one complication requiring hospitalization was noted. CONCLUSION(S): This study demonstrates that transabdominal ultrasound-guided follicular aspiration is safe and efficacious, yielding clinical results in women with significant ovarian displacement, comparable with results achieved by transvaginal aspiration in women with normally positioned ovaries. Transabdominal ultrasound-guided aspiration should be the modality of choice when the ovaries are not accessible transvaginally.